Aggressive Flu Strain Hits Early and Hard

This winter’s flu season is starting early and experts expect it to be one of the most severe in recent years, with possibly twice the normal number of fatalities.

Colorado and Texas have borne the brunt of the outbreak so far, with Colorado already reporting 6,306 confirmed cases as of Thursday, nearly three times the number incurred during the entire flu season last year.

At least seven Colorado children ranging in age from 21 months to 15 years have died so far. Normally, only two die during a typical flu season.

In Texas, at least three children and an adult have died of flu-related illnesses, as have three nursing home residents in Washington state. In New Mexico, three children and an adult died from the disease over Thanksgiving weekend.

Seven other states -- Arizona, Utah, Nevada, Idaho, Arkansas, Tennessee and Pennsylvania -- have reported widespread flu activity, according to the latest information from the Centers for Disease Control and Prevention.

“We’ve rarely seen a year where we’ve seen so many states reporting so much activity this early in the season,” said CDC’s Nancy Cox.

The influenza season normally runs from December through March, with about 10% to 20% of Americans catching it, an average of about 114,000 being hospitalized with flu-related illnesses and 36,000 dying -- a death toll that could rise to more than 70,000 this year, according to the CDC.

Those at greatest risk of death are the very young, the elderly and those with underlying health problems that make them more susceptible to the effects of an infection.

The culprit in this year’s increased activity is an influenza “A” strain called Fujian H3N2 that emerged after manufacturers began preparing this winter’s 83 million doses of vaccine.

“It’s an aggressive strain that causes more cases and more severe cases,” said Dr. Flor M. Munoz, a pediatric infectious disease specialist at the Baylor Flu Clinic in Houston. “It’s making people sicker and more likely to die.”

Although the Fujian strain is not included in the vaccine, it is closely related to the Panama H3N2 strain that is used and the vaccine should provide at least partial protection, according to the CDC.

Texas was the first state to see the effects of the virus.

Doug McBride, a spokesman for the Texas Department of Health, said this is the seventh week that the outbreak has been characterized as widespread, the highest level of activity. “The levels we’re seeing in October and early November were levels we usually see in December and January, during the height of the flu season,” he said.

Dallas County has already reported more than 1,000 confirmed cases of the disease.

Exactly why Colorado’s cases are so high continues to baffle doctors. Last summer, the state also led the nation in numbers of West Nile virus infections and deaths.

“There is no special reason why Colorado should be hit so hard, it was just bad luck,” said Dr. Eric France, chief of preventive medicine for Kaiser Permanente in Colorado. “What we are seeing here is a preview of what is going to happen nationwide.”

In some Colorado schools, nearly half of the students are out sick. Supermarkets are now setting aside space for people to get flu shots, which take about two weeks to be effective.

Kaiser hospitals and clinics in Colorado are seeing as many as 4,000 people a day seeking treatment or getting flu shots. The average doctor is seeing from 30 to 40 patients a day.

Along with the children who have died, hundreds of others have been hospitalized with flu symptoms which can include difficulty breathing, poor fluid intake, constant crying or listlessness.

California is one of a second tier of nine states that have reported regional flu outbreaks. A spokesman for the state Department of Health Services said there has been a small overall increase in cases so far, and a worrisome jump in the Central Valley.

“This week we’ve been inundated,” said Patty Henry, spokeswoman for the Kern Medical Center in Bakersfield. “There have been long waits in the emergency room.”

Children’s Hospital Central California in Madera has had 624 flu cases, verified by lab tests, in the last eight weeks compared to less than 50 at this time last year, officials said. Less than 25 of the children had to be hospitalized and there have been no deaths related to the flu.

“And this is only us,” said hospital spokeswoman Micheline Golden. “Heaven knows how many patients pediatricians have seen.”

Gregg Pullen, manager of infection control at the hospital, said the large number of cases in the Central Valley has “taxed emergency departments to the maximum.”

“It’s pretty close to a crisis,” Pullen said. “It started during the week of Nov. 10 and that’s the very earliest we have seen influenza.”

Los Angeles health authorities have also noted increases in flu activity, but “nothing alarming,” according to Dr. Laurene Mascola, director of the county’s acute communicable diseases control unit. A 5-year-old child died in Los Angeles of “flu-associated illness” on Nov. 28, but the child was visiting here from Phoenix with family and it is not clear where the disease was contracted. No other deaths have been reported in the state.

Dr. Alan L. Nager, of Childrens Hospital Los Angeles, said the hospital’s emergency room and urgent care center started seeing flu cases about a week and a half ago. But he said the cases have been “pretty mild” and the number of patients low.

“It’s just starting to blossom,” he said. “My guess is it’s going to pick up.”

Darlene Bradley, director of emergency trauma service at UC Irvine Medical Center in Orange County, said that patients are seeking medical care for flu-like symptoms in larger numbers. “We already are seeing the effects of it,” Bradley said of flu cases. “I anticipate it’s going to become much worse.”

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Times staff writers Zeke Minaya, Lianne Hart, David Kelly, Daryl Strickland, Mary MacVean, Stephanie Stassel and Jane E. Allen contributed to this report.